Solution Impregnation Method Research Articles

Performance Analysis of Vermiculite–Potassium Carbonate Composite Materials for Efficient Thermochemical Energy Storage

In this study, the preparation of the composite material consisting of expanded vermiculite (EV) and potassium carbonate (K2CO3) was conducted using a solution impregnation method. Sorption and desorption experiments were undertaken to investigate the dynamic and thermodynamic properties of the EV/K2CO3 composites with varying salt contents. The findings suggest that the EV/K2CO3 composites effectively address the issues of solution leakage resulting from the deliquescence and excessive hydration of pure K2CO3 salt, thereby substantially improving the water sorption capacity and overall stability of the composite materials. The salt content plays a vital role in the sorption and desorption processes of EV/K2CO3 composites. As the salt content rises, the resistance to sorption mass transfer increases, resulting in a decline in the average sorption rate. Concurrently, as the salt content increases, there is a corresponding increase in the average desorption rate, water uptake, and heat storage density. Specifically, at a temperature of 30 °C and a relative humidity of 60%, the EVPC40 composite with a salt content of 67.4% demonstrates water uptake, mass energy density, and volumetric energy density values of 0.68 g/g, 1633.6 kJ/kg, and 160 kWh/m3, respectively. In comparison to pure K2CO3 salt, the utilization of EV/K2CO3 composites under identical heat demand conditions results in a 57% reduction in the required reaction material. This study offers essential empirical evidence and theoretical backing for the utilization and development of EV/K2CO3 composites within thermochemical energy storage systems.

Effects of the In Situ Growth of CNTs on Ti-Coated Diamond Surfaces on the Mechanical Properties of Diamond/Aluminum Composites.

Diamond/aluminum composites have attracted significant attention as novel thermal management materials, with their interfacial bonding state and configuration playing a crucial role in determining their thermal conductivity and mechanical properties. The present work aims to evaluate the bending strength and thermal conductivity of CNT-modified Ti-coated diamond/aluminum composites with multi-scale structures. The Fe catalyst was encapsulated on the surface of Ti-coated diamond particles using the solution impregnation method, and CNTs were grown in situ on the surface of Ti-coated diamond particles using the plasma-enhanced chemical vapor deposition (PECVD) method. We investigated the influence of interface structure on the thermal conductivity and mechanical properties of diamond/aluminum composites. The results show that the CNT-modified Ti-coated diamond/aluminum composite exhibits excellent bending strength, reaching up to 281 MPa, compared to uncoated diamond/aluminum composites and Ti-coated diamond/aluminum composites. The selective bonding between diamond and aluminum was improved by the interfacial reaction between Ti and diamond particles, as well as between CNT and Al. This led to the enhanced mechanical properties of Ti-coated diamond/aluminum composites while maintaining acceptable thermal conductivity. This work provides insights into the interface's configuration design and the performance optimization of diamond/metal composites for thermal management.

Study on bulletproof performance of functionalized fabrics modified by microcapsules

AbstractThe incorporation of microcapsule particles (MPs) into fabrics offers the potential to enhance both the friction between fabric yarns and the bulletproof impact performance. In this study, MPs were prepared using the interfacial polymerization method. Furthermore, an innovative modification of the AF fabric was achieved by introducing a silane coupling agent and MPs. This resulted in the development of a microcapsules‐aramid fibers (MPs‐AF) composite material exhibiting excellent protective performance. The characterization experiment demonstrated the successful adhesion of MPs to the AF fabric, forming a robust bond between the fiber and the particles. Importantly, the modification process did not have any adverse effects on the fiber structure. The study further investigated the ballistic performance and protection mechanism of the modified fabrics through mechanical performance tests and ballistic impact tests. The yarn pull‐out experiment revealed that the MPs‐AF composite material exhibited a significant increase in pull‐out force, with a remarkable improvement of 175.6% compared to AF fabric. In the ballistic impact experiments, the MPs‐AF composite material demonstrated a substantial increase in ballistic limit velocity, rising from 52 to 118 m/s when compared to the AF fabric. These findings highlight the potential application of the MPs‐AF composite material in the field of wearable protection.Highlights Fiber surface modification grafting reaction. A simple and novel solution impregnation method was used to prepare modified AF. Preparation of microcapsule particles by interfacial polymerization. Green new fiber bulletproof material. Chemical grafting produces strong chemical bonds to increase interfacial resistance.

Synergistic integration of MoOx co-catalyst with oxygen vacancies-engineered on BiVO4 for enhancing the sensitivity of photoelectrochemical DNA biosensing

Photoelectrochemical (PEC) biosensors of deoxyribonucleic acid (DNA) hybridization with simultaneously high signal-to-noise ratio and low limit-of-detection remains greatly challenging owing to the rapid recombination of photogenerated carriers of photoelectrode. Herein, we report an efficient strategy to amplify the photocurrent signal by coupling the MoOx co-catalysts and surface oxygen vacancies (Ov) of BiVO4 as photoelectrode (MoOx/BiVO4-Ov). Using a simple in situ solution impregnation method, non-noble metal MoOx nanoparticles can be grown uniformly onto BiVO4, subsequently, abundant surface Ov of MoOx/BiVO4 is induced by N2-plasma treatment. The coupling of MoOx and surface Ov on BiVO4 can efficiently promote the separation of photogenerated carriers, as a result, the optimized MoOx/BiVO4-Ov shows an excellent photocurrent response of 300.52 μA/cm2 under simulated sunlight illumination, which is 59.6 and 5.4 times higher than that of pristine BiVO4 and MoOx/BiVO4, respectively. Furthermore, the PEC biosensor based on MoOx/BiVO4-Ov demonstrates an excellent sensitivity toward DNA hybridization (10 pM to 10 μM) with a calculated detection limit down to 0.0549 pM. Moreover, this PEC biosensor exhibits specific selectivity as well as high stability. The proposed amplification strategy by the synergistic effect of co-catalysts and defects is valuable for the construction of efficient sensors for the early diagnosis of multiple diseases.

Hydrophilic calix[4]arene dye-sensitized Co/g-C3N4 composites with Co single atoms for enhanced visible-light-driven photocatalysis

Single-atom hybrid photocatalysts (Co/g-C3N4/C4EOP) composed of hydrophilic calixarene dyes (C4EOP) and graphite-phase carbon nitrite with monodispersed Co atoms (Co/g-C3N4) are prepared by a facile solution impregnation method, and their photocatalytic performances are evaluated in visible light-driven H2 evolution from water and CO2 conversion. The optimized Co/g-C3N4/C4EOP (1.0 wt%) catalyst exhibits moderate H2 production activity (511 μmol g−1 h−1) and good durability within 60 h (TONC4EOP value of 2255) under visible light. In contrast, the Co/g-C3N4/C4BTP (1.0 wt%) and Co/g-C3N4/M-EOP (1.0 wt%) show much lower activities than Co/g-C3N4/C4EOP (1.0 wt%) under the same conditions. This could be attributed to the higher molar extinction coefficient and better hydrophilicity of C4EOP compared to C4BTP with hydrophobic alkane groups and M-EOP with single D-π-A chain. In addition, Co/g-C3N4/C4EOP (1.0 wt%) catalyst displays highly selective photocatalytic activity for CO2 reduction to CO. This work provides a promising example for the development of efficient dye-sensitized photocatalytic system based on g-C3N4 with non-noble metal for the chemical utilization of solar energy.

Enhancing the oxygen reduction reaction activity of SOFC cathode via construct a cubic fluorite/perovskite heterostructure

Pr2NiO4+δ-based (Ruddlesden-Popper) perovskite-structured oxide materials are promising candidates for low and intermediate temperature solid oxide fuel cells (SOFCs) systems. In this study, we prepared a high-performance cubic-fluorite/perovskite heterostructure Pr6O11-Pr1.2Sr0.8NiO4+δ (PO-PSNO) cathode for intermediate temperature SOFCs by solution impregnation method. By changing the impregnation amount of Pr6O11, the micro-morphology of the heterostructure was regulated, so that the heterostructure interface had the best reactive site. The oxygen reduction reaction (ORR) performance of Pr1.2Sr0.8NiO4+δ is improved, and the content of surface Sr in the heterostructure electrode material is reduced. Our results indicate that the synergistic effect of PO particles and PSNO skeleton makes the heterostructure exhibit a high oxygen surface exchange properties and catalytic performance. When the impregnation amount of PO particles reaches about 10% of the PSNO skeleton, the heterostructure has the best ORR activity. The oxygen surface exchange coefficient (Kchem) of 2-PO-PSNO is 5.8 × 10-4 cm·s−1, being 1.45 times as that of PSNO at 750 °C. Meanwhile, the polarization impedance (Rp) of 2-PO-PSNO is reduced by 66% to only 0.114 Ω cm2. Our study provides a new approach for developing high-performance RP structured perovskite cathodes and demonstrates practical applications in the field of SOFCs.

Preparation and properties of flame-retardant epoxy prepreg yarn for dry winding

The winding tension of the dry-wound forming process is uniform, the process is easy to control and the structure and performance of the prepared vehicle-mounted hydrogen composite pressure vessels are stable. Since the vehicle-mounted hydrogen pressure vessels must be subjected to rigorous fire experiments, the flame-retardant epoxy prepreg yarn technology is currently monopolized by foreign countries. The development of flame-retardant prepreg yarn with good processing properties is of great significance to the promotion and application of hydrogen pressure vessels. Here, a flame-retardant additive hexaphenoxy cyclotriphosphazene (HPCTP) was synthesized and dissolved in epoxy resin of prepreg yarn named P/N-EP. Then, the flame-retardant prepreg yarn was made by the solution impregnation method. Curing behavior, thermal analysis combustion behavior and mechanical properties of P/N-EP and tensile properties of flame-retardant prepreg yarn were investigated. Experimental results showed that the LOI value reached 36.4% at 10 phr and reached the V-0 level of the UL-94 test. The results about thermal stability of the P-N/EP resin system showed that with the increase of P-N content, T5% (temperature at 5% weight loss) and CY600 (carbon residue rate) both increased. The microstructure of carbon residue after UL-94 test was studied by electron microscope and laser Raman spectrometer. The results showed that with the increase of P-N content, the carbon layer structure became denser and the ID/IG decreased significantly, to achieve the flame-retardant effect by the condensed phase mechanism.

Flexible fabrication of a novel SiO2/AF/ZIF-L composite embedded with MOF structure and its thermal insulation properties

ZIF-L, a metal-organic framework (MOF) material, has a two-dimensional (2D) foliation, a large specific surface area, excellent thermal stability and CO2 adsorption performance, respectively. In this work, in order to further improve the thermal insulation performance of SiO2 aerogel composite fabrics, ZIF-L powder was first prepared as a reinforcing particle, and then added to silica aerogel. Finally, SiO2/AF/ZIF-L composites were obtained by solution impregnation method. The influence of different ZIF-L concentrations on the insulation performance of composites and their influencing factors were studied. Furthermore, these composites were fully characterized using BET measurement, Instron 5967, precision transient thermal performance tester, infrared thermal imager, insulation performance test, thermogravimetric analyzer, and dynamic thermomechanical analyzer. The results showed that 0.12% SiO2/AF/ZIF-L composites had excellent thermal insulation performance, with a thermal conductivity as low as 0.029 W/(m·K). In addition, SiO2/AF/ZIF-L composites fabricated by atmospheric drying method had the best thermal insulation performance under the conditions of gel time of 24 h, hydrolysis time of 5 h, and polycondensation pH value of 5–6.

Synthesis of drug carrier smart ferrogels and application of artificial neural network in modeling their doxorubicin release behavior under alternating magnetic fields

AbstractThe development of magnetic field‐sensitive smart drug delivery systems with superior properties has become an area of increasing academic and industrial importance. In this study, smart poly(NIPAAm‐co‐VSA)‐rGO/Fe3O4 ferrogels with varying concentrations of reduced graphene oxide (rGO) were synthesized. Fe3O4 nanoparticles loaded ferrogels were obtained by the in situ reduction of Fe ions. The morphologic, structural, and magnetic properties of ferrogel systems were characterized. Doxorubicin (DOX) was loaded to the synthesized ferrogels by solution impregnation method and their heating and drug release behavior over time under alternating magnetic field AMFs of 1.37, 1.64, and 1.91 millitesla (mT) were investigated. The drug loading and releasing characteristics of the ferrogel series were calculated. When the experimental results were examined, it was determined that the amount of rGO in the structure of the developed ferrogel systems had a very high effect on the magnetic, heating, and drug loading‐release characteristics of the ferrogels. To modeling their multivariable DOX release behavior, artificial neural network modeling technique was used. Calculated model performance parameters have shown that this developed artificial intelligence technique has great success in modeling complex and nonlinear DOX release behaviors.

Solar-driven evaporation device based on coal-derived nanomaterials for efficient and stable desalination

Solar-driven interfacial evaporation is considered as an effective and environmental-friendly pathway to address the issues of water shortages and pollution. Small-size evaporators with high evaporation rates based on expensive materials and complex preparation processes have been widely reported. However, attentions have rarely focused on the methods for continuous mass production of photo-thermal active materials, with which to develop a low-cost, efficient, and simple production evaporator with high performance. Herein, using low-cost materials such as coal-based carbon nanomaterial (CCN) based on wet ball milling and commercial filter paper, the CCN/filter paper evaporators are fabricated via solution impregnation method for solar-driven interface desalination. As a result, the CCN/filter paper evaporator under optimized conditions can achieve an evaporation rate of 1.40 kg m-2h−1 and conversion efficiency of 90.1%, even works in a 10% wt% NaCl solution, as well as stably working 10 h with an evaporation rate of 1.35 kg m-2h−1 without salt accumulation. Importantly, the large-scale evaporator developed for outdoor experiment can produce freshwater that meets the drinking water standard of WHO at an evaporation rate of about 6.48 kg m−2 day−1. The work demonstrates a simple and effective strategy for producing membrane evaporator with high-performance solar steam generation and superior salt rejection capability at low cost from a laboratory scale to an industrial scale, which can potentially be utilized in efficient, long-term and stable seawater desalination.

Activation of persulfate by MIL-100(Fe) coated with perylene diimide heterojunction photocatalyst for efficient removal of Bisphenol A in visible light

A new MIL-100(Fe) coated with perylene diimide (MIL-100(Fe)/PDI) heterojunction photocatalytic materials prepared by solution impregnation method. The composite material significantly promoted removal rate for Bisphenol A(BPA) under the MIL-100(Fe)/PDI/Persulfate (PS)/Visible light (Vis) system. The 0.4 g/L MIL-100(Fe)/PDI composite and 8 mM PS achieved 100% degradation of BPA at natural pH. On the MIL-100(Fe)/PDI/PS/Vis system, the kinetic rate constant of the reaction(k) was 0.08714 min−1. The enhanced degradation performance may be attributed to the transport of photo-generated electrons from PDI to MIL-100 (Fe). And this photocatalytic promotes more reactive oxygen species are produced, leading to a greatly accelerated activation of PS to produce highly reactive SO4•−. The free radical quenching assays indicated that h+, SO4•− and •OH play a dominating role. This study presents a new viewpoint for constructing heterojunction photocatalysts of Fe-based MOFs, which provides an effective way for the PS/Vis system to remove organic pollutants, and provides a new direction for building a good eco-friendly system.

Multi-functional Behaviour of Eu2O3 Embedded 3D Mesoporous Silica Template KIT-6

Rare-earth (RE) oxide embedded ordered mesoporous silica have been successfully prepared via a solution impregnation method. The structure and physical property of the nanocomposites (NCs) were studied by low-angle X-ray diffraction, Transmission Electron Microscopy (TEM), Photoluminescence (PL) and magnetic measurement. The NCs exhibited the room temperature transition emission due to the presence of Eu3+ ions. Also the NC system showed a room temperature weak ferromagnetism due to the large oxygen vacancy present in the system. Photoluminescence, magnetic property and large surface area, make these NCs ideal multi-functional materials, which will have potential applications in the field of bio-medicine and drug-delivery. These kinds of nanocomposites are promising candidates for fabrication of various environment friendly smart devices.

Construction and Adsorption Performance Study of GO-CNT/Activated Carbon Composites for High Efficient Adsorption of Pollutants in Wastewater.

Based on the increasing application requirements for the efficient adsorption of wastewater pollutants, graphene oxide-carbon nanotube/activated carbon (GO-CNT/AC) composites are constructed from the optimal microstructure matching of GO, CNTs, and AC materials by solution impregnation and freeze-drying methods. Three-dimensional structures with nano-micro hierarchical pores are established, with GO and CNTs uniformly dispersed on the AC surface, effectively restrain the agglomeration. The added CNTs played a "spring" role, supporting the gap between the GO sheets and AC matrix. Meanwhile, stable links are formed between GO, CNTs, and AC, realizing the synergistic matching of the microstructure, which provides abundant active absorption sites beneficial for improving the adsorption performance. The influences of the CNT contents, adsorbent amounts, methylene blue (MB) concentrations, and pH values on the adsorption property of GO-CNT/AC composites are systematically investigated. The results show that when the pH value of the MB solution is 13, the CNT concentration is 3 mg/mL and the MB concentration is 200 mg/L, the adsorption property of the composite is the best, with an adsorption capacity of 190.8 mg/g and a removal percentage of 95.4%. Compared with the raw AC, the adsorption capacity and removal percentage of the composites are increased by 73.9% and 72.8%, respectively. The GO-CNT/AC composites exhibit excellent cyclic adsorption performance, with a cyclic stability of 91.8% after six rounds of adsorption-desorption cycles. The kinetic analysis shows that the adsorption process conforms to the PSO kinetic model. By fitting of the IPD model, the adsorption mechanisms of the GO-CNT/AC composites are divided into two adsorption stages and described respectively. This study provides a new way to achieve highly efficient adsorption of pollutants in wastewater.

Ni@rGO into nickel foam for composite polyethylene glycol and erythritol phase change materials

The exploitation of shape-stabilized composite phase change materials (CPCMs) with high solar-thermal conversion efficiency, thermal storage capacity and thermal conductivity has attractive prospects for solar energy utilization. In this work, reduced graphene oxide (rGO) nanosheets decorated with Ni nanoparticles (Ni@rGO) are successfully filled into the nickel foam (NF) skeletons by acidic graphene oxide solution impregnation and subsequent thermal reduction methods. The obtained NF/Ni@rGO supports with controllable Ni@rGO content are used as the carrier for loading polyethylene glycol (PEG) and erythritol (ET) to prepare CPCMs. The Ni@rGO hybridization enhances the interaction of the carrier framework with the PCM, which can effectively increase the PCM loading and prevent its leakage. As compared with bare NF supported CPCMs, the NF/Ni@rGO supported CPCMs have better shape stability, far higher thermal storage density, and better recyclability. The optimized CPCMs with PEG and ET show high latent enthalpies of 125.30 J·g−1 and 280.66 J·g−1, respectively. It is also found that the thermal conductivity of CPCMs is significantly improved to 0.9199 W·m−1K−1 for NF/Ni@rGO-10/PEG and 0.9146 W·m−1K−1 for NF/Ni@rGO-10/ET, which is 344 % and 35 % higher than that of PEG and ET, respectively. In addition, the decoration of Ni nanoparticles on the rGO support (i.e., NF/Ni@rGO-10) could further improve the thermal conductivity, solar-thermal conversion efficiency (95.74 %) and electro-thermal conversion efficiency (71.39 %) of CPCMs. This research furnishes the basis for the development of high performance CPCMs. Moreover, it has great potential and broad application prospects in the efficient utilization of solar energy and thermal management of electronic devices.

Modeling the effect of physical crosslinking degree of pH and temperature responsive poly(NIPAAm-co-VSA)/alginate IPN hydrogels on drug release behavior

There is a growing demand to design and development of hydrogel based stimuli responsive drug-delivery systems due to possess several advantages, namely high drug loading capacity, target specific delivery, biocompatibility, reduced drug toxicity and controlled drug release. Because their drug release behavior is dependent on many factors, it is very difficult to accurately characterize these behaviors. So, the characterization of drug loading and release behaviors is very important from an industrial and academic point of view. In this study, pH and temperature responsive poly(NIPAAm-co-VSA)/Alginate interpenetrating polymer network (IPN) hydrogel was synthesized by free radical polymerization in the presence of Poly(NIPA-co-VSA) nano gels. Na-Alginate natural polymer was used to physically cross-link the hydrogels with the Ca2+ ions. To obtain physically crosslinked hydrogel series at different rates, hydrogels were kept in various concentrations of CaCl2 solutions. The mechanical, chemical and morphological properties of obtained hydrogel series were characterized by compression test, FT-IR and SEM analysis techniques. As a result of the mechanical tests, it was determined that the fracture strengths varied between 137 and 830 kPa. The doxorubicin (DOX) loading capacities of the hydrogels were determined to be between 86 and 161 mg DOX/g polymer by the solution impregnation method. Their DOX release behavior have been investigated as a function of time, pH, temperature and physical crosslinking degree of hydrogel. Experimentally obtained and highly complex DOX release behaviors were successfully modeled with the artificial neural network (ANN) technique.

Shape-controlled silver nanoplates colored fabric with tunable colors, photothermal antibacterial and colorimetric detection of hydrogen sulfide

Anisotropic silver nanoplates are widely anticipated in multifunctional textiles, but their large-scale promotion is limited by the shortcomings of long reaction time, uncontrollable shape and low yield in the preparation process. In this study, a microwave-assisted strategy is provided to prepare shape-controllable silver nanoplates for coloration of non-woven fabric. Anisotropic Ag nanoplates are efficiently coated on the surface of chitosan-pretreated fabric by a simple solution impregnation method, which generates the fabric with tunable color and multiple functions. The Ag nanoplates loaded fabric exhibits excellent photothermal properties at 808 nm laser irradiation due to its unique plasmonic absorption features. Colored fabric shows a strong synergistic antibacterial effect, including silver ion release and hyperthermia caused by the photothermal effect under near-infrared (NIR) light. Additionally, colored fabrics can be used as colorimetric sensors for selective detection of H2S. The colorimetric values of visible color signal of fabric-based H2S gas sensor can be real-time precisely detected using a smartphone, enlightening its high potential as a wearable toxic gas alarm device for the simple and rapid detection of hazardous gases.

Highly stable cathode materials for aqueous Zn ion batteries: Synergistic effect of pre-inserted bimetallic ions in vanadium oxide layer

Aqueous Zn ion batteries with cost-effectiveness, high safety, and eco-friendliness have a great potential as an excellent substitute for non-aqueous cells for large-scale energy storage. However, the intercalation of Zn 2+ ions in the cathode materials is challenging and complex due to the sluggish diffusion kinetics of Zn 2+ ions. Herein, the highly reversible Zn ion battery based on vanadium oxide nanobelts has been developed by using pre-inserted bimetallic ions (Na + and Ca 2+ ions) within the vanadium oxide layer (NCVO) as the cathode and Zn(CF 3 SO 3 ) 2 solution as an electrolyte. Vanadium oxide nanobelts which were calcined at 350 °C (NCVO-350) deliver the superior cycle stability with a capacity retention rate close to 100% after 200 cycles at 0.5 A g −1 , and 92% retention is also achieved after 3000 cycles at 10 A g −1 . The ultrahigh capacity retentions at low/high current densities are attributed to the pre-inserted bimetallic ions within the layers to enhance the structural stability of the vanadium oxide nanobelts. Moreover, the low-cost electrode material preparation process will accelerate the industrialization of aqueous Zn ion batteries. • A simple solution impregnation method at ambient conditions is proposed. • The conversion of vanadium-based materials from nanoparticles to nanobelts. • Amorphous structure of electrode also can enhance Zn-storage performances. • Bimetallic ions nanobelts exhibit promising electrochemical performance.

Sorption characteristics of K2CO3-based thermochemical material for thermal energy storage

The selection of a suitable thermochemical material (TCM) is essential for sorption thermal energy storage (TES) systems. Among many TCMs, K2CO3 is considered a promising candidate. A major challenge in the application of pure K2CO3 for TES is the low sorption rate, which can be improved effectively by employing a porous matrix. In this study, we prepared a K2CO3-based composite with a salt content of 85.7% by using a solution impregnation method. Immediately afterwards, its sorption characteristics were investigated at different thicknesses, morphologies and working conditions. The result showed that the sorption rate of the K2CO3-based composite is more than four times higher than that of pure K2CO3, and the mass and volume heat storage densities are approximately 608.5 kJ/kg and 214.7 kWh/m3, respectively, indicating that this composite may be competitive in TES applications.

Enhanced zinc ions storage performance by calcium ion induction/anchoring of vanadium-based nanobelts at low temperature

Low-cost, high abundance, environmentally friendly, and intrinsic safety endow the aqueous Zn ion batteries a bright prospect for large-scale energy storage. However, it is still challenging to find suitable cathode materials with excellent Zn2+ ion storage performance due to sluggish Zn2+ ions intercalation kinetics. Herein, we prepare the novel nanobelts as advanced cathode materials via a simple solution impregnation method. Firstly, the Ca2+ ions promote the conversion of vanadium-based materials from nanoparticles to nanobelts, and also act as a pillar to stabilize the structure of the vanadium-based material. Furthermore, the amorphous structure of the electrode also can be tuned by subsequent appropriate calcination, aiming to enhance Zn-storage performances. Thus, the cathode materials exhibit the superior electrochemical performances with a high-capacity retention rate of 93.75% at 0.5 A/g after 100 cycles and a capacity retention rate of 91.3% after 3000 cycles at 5 A/g. In addition, the flexible quasi-solid-state Zn ion batteries with Ca2+ ions pre-intercalated vanadium-based oxide as cathode is also investigated, and show stable electrochemical properties under bending states. With the cost-effective and green large-scale synthesis process, the outstanding electrochemical performance of cathode shed light on the rational design of novel cathodes for practical aqueous Zn ion batteries.

A Facile Molding Method of Continuous Fiber-Reinforced Thermoplastic Composites and Its Mechanical Property.

The mechanical properties of continuous fiber-reinforced thermoplastic (C-FRTP) composites are commonly lower than those of continuous fiber-reinforced thermosetting plastic (C-FRP) composites. We have developed a new molding method for C-FRTP. In this study, pre-impregnated materials were successfully prepared by polymer solution impregnation method and, finally, C-FRTP was fabricated. The viscosity of the thermoplastic matrix was decreased to approximately 3dPa×s, the same level of epoxy, and the fiber volume fraction was increased from approximately 45 to 60%. The cross-section of specimens were polished by an ion milling system and impregnation condition was investigated by scanning electron microscopy (SEM). The micrographs suggested that thermoplastic polymer was impregnated to every corner of the fiber, and no void was found on the cross-section. It revealed that void-free composites with perfect mechanical properties can be manufactured with this new molding method. All specimens were submitted to a mechanical measuring equipment, and the mechanical properties of the composite specimens were investigated. Mechanical analysis revealed that tensile property and flexural property of C-FRTP were enhanced up to the same level with C-FRP.